So I spent some time crawling around under her this evening, she won't be on the road until title and tags show up, so plenty of time to kill getting to know her better. Looks pretty good, the transfer case was replaced not to long ago, the rebuilt case is dated 2007. While examining it, I noticed that the input to the first rear axle from the transfer case was missing some bolts. Sure enough, it was missing three, and the other 5 that were installed were finger tight!!!
So, into the garage, found the same size and length bolts and nuts, and installed them where they belonged, and tightened up the rest, it was clear from their threads that the ones in place, had been rattling around in location for quite a bit of time...
The output flange from the transfer case had all it's bolts and nuts, but 1/2 of them were finger tight. I'm guessing the transfer case replacement was recent, and someone forgot to torque everything back down like they should have.
I'll spend a few more hours underneath her going through everything. All of the ABS components appear very new, as in no road grime on them at all, so it must have been a recent update, as it has a nice hanging tag in the cab talking about the wonders of ABS brakes and it has a nice yellow sticker in the windshield denoting the ABS system. Where any A2 trucks built without ABS? I had thought I had read that only A1 trucks required the update.